Hand grenade



H. L. STHYR HAND GRENADE Jan. 17, W39.

Filed May 15, 1937 3 Sheets-Sheet l INVENTOR HERMAN L. STH'YR ATTORNEYS H. L. STHYR HAND GRENADE Jan. 17, 1939.

Filed May 15, 1937 3 Sheets-Sheet 2 INVENTOR HERMAN L. STHYR By ATTORNEYS H. L. STHYR Jan. 17, 1939.

HAND GRENADE Filed May 15, 1957 3 Sheets-Sheet 5 HERMAN L. STHYR abbot/M4435 Patented Jan. 17, 1939 UNi'i'EQ STATES FATENT OFFICE Application May 15, 1937, Serial No. 142,909 In Great Britain May 18, 1936 11 Claims.

This invention relates to improvements in hand grenades and has more particular reference to the type in which the operation for detonation of the grenade is effected by relative movement between two of its component parts.

The object of the invention is to provide the above mechanism within the minimum of space and yet ensure certainty of action, and also wherein the detonator and fuse are capable of being centrally disposed within the body of explosive charge, the whole assembly being entirely waterproof, and the grenade safe until thrown or a relative degree of axial motion imparted to its components.

The invention consists of a hand grenade having a detonator and a time fuse characterized that said time fuse is inflamed or fired by the act of throwing said grenade, having two operating but independent parts, the one part constituting the grenade proper, and the other a holding or containing member adapted to be grasped by the thrower, the relative movement of said parts about their common axis operating the device employed for detonation.

The invention further comprises means whereby the grenade can be locked in a safe or firing condition by a trigger and when locked in a safe condition the interior is accessible only by rotation of the container relatively to the grenade for insertion, inspection or removal of the time fuse and detonator, and when locked in a firing condition relative motion between the parts is only possible in an axial direction.

The invention further comprises means to indicate at night the trigger position by feel; a sufficient length of handle or container to assist flight as a sling, and means to ensure a definite requisite compression upon the striking pin spring before release of said pin can take place, and the shaping of the pin tail and/or the gripping jaws that the latter are compelled to open when the restraining device is passed.

In order that the invention may be fully understood reierence is made to the accompanying drawings in which preferred embodiments of the invention are illustrated.

Fig. 1 is a part sectional elevation, on line AA of Fig. 2, of the invention, when the trigger is in the firing position.

Fig. 2 is a plan of the base of Fig. 1 looking up.

Fig. 3 is a side part sectional elevation at 180 to that appearing in Fig. 1.

Fig. 4 is an elevation of the lower part of the innermost tube.

Fig. 5 is a vertical section of the base portion of the grenade.

Fig. 5a is a part sectional plan and part sectional elevation on line B-B of Fig. 5 showing the locking pins in position for removal of the innermost tube.

Fig. 6 is a vertical section of the base portion of the grenade showing the locking pins situated in the safe position.

Fig. '7 is a vertical section similar to Fig. 6 but showing the locking pins as they would be situated for the firing position.

Fig. 8 is a side elevation of the assembled grenade.

Fig. 9 is a side elevation, showing the invention applied to a stick grenade.

Fig. 10 is a sectional elevation of Fig. 9.

Fig. 10a is a transverse section taken on the line l0dl0a in Fig. 10.

Fig. 11 is a detailed view showing the detachable portion after operation.

Fig. 12 is a vertical section, showing a modification of Fig. 9.

Referring to the drawings and to Figs. 1 to 8, I is the shell comprising the body part of the grenade proper. This is formed as a cast metal body having a filling hole 2, a seating socket 3, a slightly protruding ring 4 adapted to allow the container or handle part 5 to lie flush with the body part of the grenade. The base of the grenade la is formed as shown and has an internal groove 6 which accommodates a beaded in edge of the base of the inner tube 1. The object of the tube 1 is to separate the mechanism from the bursting charge. The tube 1 is formed with shoulders 8 and an enlarged tubular extension 9. The upper part l0 fits into the socket 3 formed in the internal crown of the grenade. The container 5 is formed with a recessed cavity II, in which is situated the trigger I2 engaging a circular spring member l3, and is mounted upon the squared spindle M of the sealing plug IS. The sealing plug l5 has a headpiece carrying a transverse hinge pin [6, upon which the jaws I! are pivoted and adapted to grip the tail of the striking or firing pin [8. The sealing plug 55 has a circular shank l9 which passes through a key 20 fast with the base of the container 5, and then passes through a rubber or equivalent washer 2| and metal washer 22, its square continuation passing through the centre 23 of the trigger l2 and protruding therefrom and kept in position by a split pin 24 accommodated in a hole in the shank M.

The key 20 on the base of the container is accommodated in a slot 230. (Fig. 4) cut in the innermost tube 25 and employed to rotate and thereby screw or unscrew the innermost tube 25 when theouter container is rotated.

Within the inner tube I is mounted the innermost tube 25. This part is tubular in construction and forms in its upper part a seating for the percussion cap fuse and detonator unit, hereinafter called the fuse unit. The said tube 25 is formed with an internal flange 27 to accommodate a spring 28 and below said flange is provided with a circular cavity 29, in which the pivoted locking jaws I! are free to move.

The wall of the innermost tube is provided with horizontal slots 35 and an axial slot 35 at opposed points (see Fig. 4) which are parts of bayonet slots within which the'pin is can move, said pin protruding beyond said walls and entering a like slot 3| cut in the base in of the grenade shell I. The innermost tube 25 is also provided with two opposed projections 32 operating in slots 33 cut in the base of the grenade shell I (see Figs. 5, 6 and '7). The slots 3! and 33 formed inthe base of the grenade are parts of bayonet slots which are transverse to the longitudinal axis of the grenade. These enter anaxial slot 34 which permits the projections 32 and pin I 6 both to slide freely down this slot 34 when movement of the innermost tube under rotation of the container relatively to the grenade takes place, so that the container 5 with the innermost tube 25 attached can be withdrawn: axially to insert, in-

. spect or withdraw the fuse unit '26 (see Fig. 5).

When the triggerIZ is moved to the firing position the vertical slot 35 cut in the innermost tube is coincident .with'the vertical slot 34 cut in the base of the grenade, and the pin I6 is free to move downwardly in the groove as shown in Fig. 7. At this position the projection 32 is at the end of the slot 33 and the innermost tube therefore locked in position within thegrenade.

The striking pin I8 is formed with a tail piece l8a having undercut sloping sides which engage the sides of the gripping jaws I1 and tend to open said jaws when under relative movement between the container 5 and grenade I the said jaws have passed the confines of the circular cavity 29 at the base of the innermost tube 25.

The striking pin I8 is formed with a head 36, gas channels 36a and a central fire or rim firing device 31. The spring 28 which is under no compression or only very slight compression in the asembled condition shown in Fig. 1 surrounds the shank of the firing pin I 8, and reacts between the internal flange 2'! of the innermost tube 25 and the underside of pin head 36. The fuse unit 26 is of a known character, having a percussion cap 38, a fuse 39 and a detonator head 40. The latter is adapted to nest closely within the walls of the inner tube 1 to detonate the bursting charge 4| contained within the grenade body I.

The spring I3 is formed as a circular member less in diameter than the internal cavity of the base and having a safe detent 42 and a firing detent 43. In the view shown in Fig. 2 the trigger I2 is in the firing position and corresponds to the position occupied by the cross pin IS in Fig. '7. The spring is tempered and tends when the trigger is free of one detent to force the trigger into the other detent. An indicator pin 44 is attached to the spring I3 so that the user can tell by feel in the dark whether the grenade is set into the firing position or is safe.

An adhesive band 45 is adapted to be wound round the junction of the container and the ring projection 4 of the grenade, so as to provide a waterproof closure of the whole device. This band 45 may also be provided with a ring 46 to 7 enable the band to be readily detached for use.

The operation of the device is as follows:--

Assuming the hand grenade to be in the condition as shown in Fig. 1 (excepting that the fuse unit requires insertion), to insert the fuse unit the trigger I2 is moved into the safe position.

This brings the projections 32 and cross pin l6 into the position shown in Fig. 6. The container is now rotated to the left, whilst the topof the grenade is held. The key 20 maintains turning movement to the innermost tube by engaging slot 28a. This has the effect of moving both the cross pin and the innermost tube with the projection 32 into alignment over the vertical slot 34, allowing the container to be now withdrawn with the innermost tube attached thereto and the fuse unit 26 inserted, (see Fig. 5). In order to keep the'said fuse unit in a correct position upon the innermost tube, a conical shaped cover 47 is pressed over the fuse unit and engages the side walls of the innermost tube 25. The container and its associated parts, i. e. the innermost tube 25 and the fuse unit 26 can now be inserted within the'grenade, and if the container 5 is now rotated from left to right, the projections 32 and the pin IE will occupy the position shown in Fig. 6 when no movement of the parts is possible and the grenade is safe, the trigger remaining. in the position of safe as described above. If new the trigger is movedto fire the spring I 3 is positioned back by the forefinger and the trigger turned until the shoulder enters the notch 43. 1'

This pushes the spring outwards causing the button or pin 44 to protrude through the side of the container 5 warning the user that the grenade is ready to fire.

In throwing the grenade the user grips the container or handle part 5 keeping the thumb during the backward swing on the upper part of the grenade I (see Fig. 8). 0n the forward swing the thumb is brought on to the container and the container used as a sling to assist in urging the throw of the grenade forward. This action causes relative motion between the container and its parts and the grenade and its parts. Hence the jaws I! of the gripping device, which hold the tail of the striking pin [8 draw the latter down, compressing the spring 28 until the jaws pass beyond the limit of the cavity 29 at the base of the innermost tube 25, when due to the shape of the jaws and the tail piece 80. of the striking pin l8 the jaws separate, allowing the spring suddenly to re-act and urge the striking pin forward to detonate the percussion cap 38 of the fuse unit 26. When the trigger is turned to fire, see Fig. 7, the projections 32 are at the ends of the transverse slots 33, whilst the pin I6 has moved into the vertical slots'34 and 35, and is therefore free to move downwards.

It will be observed by reason of the above mechanism that it is impossible to fire the grenade.

during any attempt to inspect the detonator, since to obtain access to the detonator the trigger must be in the safe position, and in fact unless the trigger is in the fire position the grenade is safe. Further, in the safe position no relative axial motion is possible between the container and the grenade. 7

It will further be observed that in the safe condition there is practically no tension upon the striking pin spring 28, so that the grenade is safe in transit, and even if the tail of the striking pin were to snap, no harm would result.

Due to the adhesive waterproofing band 45 and rubber washer 2|, the grenade can be immersed in water without harm, the whole of the working parts being protected against the intrusion of damp even during prolonged periods of storage. Again, when the trigger is set to fire, unintentional rotation of the canister against the grenade is impossible in either direction, since the pin 16 is hard against the wall of the groove 34, whilst the projection 32 is hard against the end of the slot 33 (see Fig. 7). This point is of importance in that the grenade could otherwise be set to fire, and an attempt made to remove the fuse unit and by relative axial movement cause detonation. The construction described above renders such a happening impossible.

It will equally be noted that the length of travel of the jaws I 1 within the cavity of the innermost tube 25 compels a definite compression of the spring 28, for operation, the spring otherwise remaining substantially without compression and therefore without fatigue when the grenade is not in use.

It is found that the sling action of the container is noticeably marked, as a much further distance can be achieved in properly using the container as a sling than in attempting to hurl the grenade without its assistance.

Figs. 9, 10 and 11 show the invention as applied tothe stick type of grenade. In this type the grenade proper I has a screwed extension 55 into which is detachably secured a tubular member 5!. The grenade is provided with an inner tube I and a fuse unit 26, and the base Ia of the grenade accommodates the percussion head 38 of the fuse unit 26. The tubular member 5! houses the striking pin 18. The spring 28 has an abutment formed by the screws Ha. A wooden or like covering 52 surrounds the tubular member 5!, which does not continue the full length thereof, the said handle being divided into two portions, the lower portion or handle part 53 being a detachable unit allied to the container or handle part 5, in that this portion is used to contain the gripping jaws H which engage the tail end I8a of the striking pin 18. The tubular member penetrates into the portion of the handle 53 and is slotted as shown in Fig. 11 to accommodate the cross pin l6, whose operation is identical with that illustrated in the first type above described. The lower portion of the handle 53 is lined with a metal inset 54, one side of which is slotted and inbent as shown at 55 to engage indentations 56 and 56a formed in the base of the tubular member 5!. In this type of device the tubular member 5| is unscrewed from the grenade to insert, inspect or remove the fuse unit 26. After insertion of the fuse unit the grenade can be locked in the safe position when no relative movement is possible between the parts. If, however, the lower part 53 is rotated to the fire position, which brings the cross pin I 6 into line with the axial portion of the bayonet slot 35, the inbent detent 55 is moved out of the slot 56 into slot 56a and the lower part of the handle 53 is free to have relative axial movement in respect of the upper portion.

To throw the grenade, and on the backward swing the user grips the lower portion 53 with the thumb resting on the upper portion 52. On the forward swing the thumb is removed and the grenade thrown, the portion 53 and. its associated parts, including the gripping jaws, remaining in the hand of the thrower whilst the rest of the missile travels through the air. This has the effect of drawing down the striking pin l8 until the jaws pass the lowermost end of the innermost tube 5|, when they swing open allowing the striking pin l8 to slide under spring force to detonate the percussion cap 38 and inflame the fuse.

In Fig 12 a modification is shown wherein the gripping jaws, striking pin and spring are omitted, and a match composition and friction match striker M are employed of known type attached to the base of the fuse. With this type a string or cord 60 having a sufficiency of length is attached to the friction match and pin 55, see Fig. 12, so that when the grenade is thrown the lower part 53 detaches and. carries away the string 65 and friction striker 6|.

I claim:

1. A hand grenade including a body part, a striking mechanism comprising a slidable striker and an actuating spring therefor, a handle part mounted to slide relatively to said body part and detachable therefrom, a coupling device between said handle part and said striker and releasable by relative sliding movement between said handle part and body part, and guide means for preventing premature release of said coupling device, said handle part and coupling device being movable relatively to retract said striker and to free said coupling device from said guide means.

2. A hand grenade of the kind referred to comprising a body part to contain an explosive charge, a handle part relatively movable axially of the body part, a striking pin, a pivot pin attached to the handle part, a pair of self-releasing gripper jaws mounted to rock on said pivot pin and controlling the striking pin, and guide means on the body part normally constraining said gripper jaws to engage and hold the striking pin, the body part being provided with a bayonet slot having a transverse part into which said pivot pin is movable to retain said jaws in holding engagement with the striking pin and thereby set the grenade in safe condition and having an axial part into which the pivot pin is movable to set the grenade in firing condition and permit the handle part to move axially relatively to the body part and thereby free said gripper jaws from said guide means and thus release the striking pin.

3. A hand grenade as claimed in claim 2, wherein said body part comprises a releasable internal tube to contain the striking pin and provide the guide means for the gripper jaws and having a bayonet slot for the pivot pin, and a further bayonet joint between said tube and body part operative by a partial relative rotation of the handle part and body part of the grenade to releasably secure said internal tube in the body part.

4. A hand grenade as claimed in claim 2, wherein said body part comprises a releasable internal tube to contain the striking pin and provide the guide means for the gripper jaws and having a bayonet slot for the pivot pin, a further bayonet joint between said tube and body part operative by a partial relative rotation of the handle part and body part to releasably secure said internal tube in the body part, and a trigger device for moving said pivot pin into or out of the transverse part of said bayonet slot in the body part to set the grenade in the safe or firing condition and providing an interlocking action with said further bayonet joint which prevents release of the latter to permit withdrawal of the internal tube from the body part unless the pivot pin is engaged in the transverse part of the bayonet slot in the inner tube. V

5. A hand grenade as claimed in claim 2, wherein said handle part comprises a container which partly envelopes the body part of the grenade.

6. A hand grenade as claimed in claim 2, wherein the movement of said pivot pin in said bayonet slot is controlled by a trigger device which is accommodated in a cavity in the base of said handle part.

'7. A hand grenade as claimed in claim 2, wherein the movement of said pivot pin in said bayonet slot is controlled by a trigger device which is housed in the base of the handle part, and an indicator member movable by the trigger device to a position in which it projects from the base of the handle part when the trigger device is set to the firing position.

8. A hand grenade as claimed in claim 2, wherein said handle part comprises a container which partly envelopes the body part, and an adhesive band applied to the junction of the handle part and the body part for sealing the same against ingress of moisture during storage and transport.

9. In a hand grenade as claimed in claim 2,

wherein the body part comprises a fixed inner tube to act as a separator between the explosive charge and firing mechanism, and the guide means in the body part comprises a removable innermost tube carrying the striking pin, time fuse and detonator, said innermost tube having a bayonet joint connection with the body part and having a key slot in its base, and a key attached to the base of the handle part for effecting rota-' tion of the innermost tube for insertion or removal.

10. A hand grenade as claimed in claim 2, wherein said guide means comprises a removable internal tube carrying the striking pin and having a fuse and a detonator positioned and secured in fixed position thereon.

11. A hand grenade as claimed in claim 2, wherein the body part of the grenade has an extension which contains the striking pin and its actuating spring, and a further extension axially movable in respect of the first mentioned extension and carrying the striking pin gripping jaws, whereby relative axial movement of said further extension in respect of the first mentioned extension tensions said spring and releases the striking pin to detonate the fuse.

HERMAN LUDVIG STHYR. 

